Methods of Filling Openings with Conductive Material, and Assemblies Having Vertically-Stacked Conductive Structures

ABSTRACT

Some embodiments include a method in which an assembly is formed to have voids within a stack, and to have slits adjacent the voids. Peripheral boundaries of the voids have proximal regions near the slits and distal regions adjacent the proximal regions. A material is deposited within the voids under conditions which cause the material to form to a greater thickness along the distal regions than along the proximal regions. Some embodiments include an assembly having a stack of alternating first and second levels. The second levels include conductive material. Panel structures extend through the stack. The conductive material within the second levels has outer edges with proximal regions near the panel structures and distal regions adjacent the proximal regions. Interface material is along the outer edges of the conductive material and has a different composition along the proximal regions than along the distal regions.

TECHNICAL FIELD

Methods of filling openings with conductive material, and assemblieshaving vertically-stacked conductive structures.

BACKGROUND

Memory provides data storage for electronic systems. Flash memory is onetype of memory, and has numerous uses in modern computers and devices.For instance, modern personal computers may have BIOS stored on a flashmemory chip. As another example, it is becoming increasingly common forcomputers and other devices to utilize flash memory in solid statedrives to replace conventional hard drives. As yet another example,flash memory is popular in wireless electronic devices because itenables manufacturers to support new communication protocols as theybecome standardized, and to provide the ability to remotely upgrade thedevices for enhanced features.

NAND may be a basic architecture of flash memory, and may be configuredto comprise vertically-stacked memory cells.

Before describing NAND specifically, it may be helpful to more generallydescribe the relationship of a memory array within an integratedarrangement. FIG. 1 shows a block diagram of a prior art device 100which includes a memory array 102 having a plurality of memory cells 103arranged in rows and columns along with access lines 104 (e.g.,wordlines to conduct signals WL0 through WLm) and first data lines 106(e.g., bitlines to conduct signals BL0 through BLn). Access lines 104and first data lines 106 may be used to transfer information to and fromthe memory cells 103. A row decoder 107 and a column decoder 108 decodeaddress signals A0 through AX on address lines 109 to determine whichones of the memory cells 103 are to be accessed. A sense amplifiercircuit 115 operates to determine the values of information read fromthe memory cells 103. An I/0 circuit 117 transfers values of informationbetween the memory array 102 and input/output (I/O) lines 105. SignalsDQ0 through DQN on the I/O lines 105 can represent values of informationread from or to be written into the memory cells 103. Other devices cancommunicate with the device 100 through the I/O lines 105, the addresslines 109, or the control lines 120. A memory control unit 118 controlsmemory operations to be performed on the memory cells 103 utilizingsignals on the control lines 120. The device 100 can receive supplyvoltage signals Vcc and Vss on a first supply line 130 and a secondsupply line 132, respectively. The device 100 includes a select circuit140 and an input/output (I/O) circuit 117. The select circuit 140 canrespond, via the I/O circuit 117, to signals CSEL1 through CSELn toselect signals on the first data lines 106 and the second data lines 113that can represent the values of information to be read from or to beprogrammed into the memory cells 103. The column decoder 108 canselectively activate the CSEL1 through CSELn signals based on the A0through AX address signals on the address lines 109. The select circuit140 can select the signals on the first data lines 106 and the seconddata lines 113 to provide communication between the memory array 102 andthe I/O circuit 117 during read and programming operations.

The memory array 102 of FIG. 1 may be a NAND memory array, and FIG. 2shows a block diagram of a three-dimensional NAND memory device 200which may be utilized for the memory array 102 of FIG. 1. The device 200comprises a plurality of strings of charge-storage devices. In a firstdirection (Z-Z′), each string of charge-storage devices may comprise,for example, thirty-two charge-storage devices stacked over one anotherwith each charge-storage device corresponding to one of, for example,thirty-two tiers (e.g., Tier0-Tier31). The charge-storage devices of arespective string may share a common channel region, such as one formedin a respective pillar of semiconductor material (e.g., polysilicon)about which the string of charge-storage devices is formed. In a seconddirection (X-X′), each first group of, for example, sixteen first groupsof the plurality of strings may comprise, for example, eight stringssharing a plurality (e.g., thirty-two) of access lines (i.e., “globalcontrol gate (CG) lines”, also known as wordlines, WLs). Each of theaccess lines may couple the charge-storage devices within a tier. Thecharge-storage devices coupled by the same access line (and thuscorresponding to the same tier) may be logically grouped into, forexample, two pages, such as P0/P32, P 1/P33, P2/P34 and so on, when eachcharge-storage device comprises a cell capable of storing two bits ofinformation. In a third direction (Y-Y′), each second group of, forexample, eight second groups of the plurality of strings, may comprisesixteen strings coupled by a corresponding one of eight data lines. Thesize of a memory block may comprise 1,024 pages and total about 16 MB(e.g., 16 WLs×32 tiers×2 bits=1,024 pages/block, block size=1,024pages×16 KB/page=16 MB). The number of the strings, tiers, access lines,data lines, first groups, second groups and/or pages may be greater orsmaller than those shown in FIG. 2.

FIG. 3 shows a cross-sectional view of a memory block 300 of the 3D NANDmemory device 200 of FIG. 2 in an X-X′ direction, including fifteenstrings of charge-storage devices in one of the sixteen first groups ofstrings described with respect to FIG. 2. The plurality of strings ofthe memory block 300 may be grouped into a plurality of subsets 310,320, 330 (e.g., tile columns), such as tile column_(I), tile column_(j)and tile column_(K), with each subset (e.g., tile column) comprising a“partial block” of the memory block 300. A global drain-side select gate(SGD) line 340 may be coupled to the SGDs of the plurality of strings.For example, the global SGD line 340 may be coupled to a plurality(e.g., three) of sub-SGD lines 342, 344, 346 with each sub-SGD linecorresponding to a respective subset (e.g., tile column), via acorresponding one of a plurality (e.g., three) of sub-SGD drivers 332,334, 336. Each of the sub-SGD drivers 332, 334, 336 may concurrentlycouple or cut off the SGDs of the strings of a corresponding partialblock (e.g., tile column) independently of those of other partialblocks. A global source-side select gate (SGS) line 360 may be coupledto the SGSs of the plurality of strings. For example, the global SGSline 360 may be coupled to a plurality of sub-SGS lines 362, 364, 366with each sub-SGS line corresponding to the respective subset (e.g.,tile column), via a corresponding one of a plurality of sub-SGS drivers322, 324, 326. Each of the sub-SGS drivers 322, 324, 326 mayconcurrently couple or cut off the SGSs of the strings of acorresponding partial block (e.g., tile column) independently of thoseof other partial blocks. A global access line (e.g., a global CG line)350 may couple the charge-storage devices corresponding to therespective tier of each of the plurality of strings. Each global CG line(e.g., the global CG line 350) may be coupled to a plurality ofsub-access lines (e.g., sub-CG lines) 352, 354, 356 via a correspondingone of a plurality of sub-string drivers 312, 314 and 316. Each of thesub-string drivers may concurrently couple or cut off the charge-storagedevices corresponding to the respective partial block and/or tierindependently of those of other partial blocks and/or other tiers. Thecharge-storage devices corresponding to the respective subset (e.g.,partial block) and the respective tier may comprise a “partial tier”(e.g., a single “tile”) of charge-storage devices. The stringscorresponding to the respective subset (e.g., partial block) may becoupled to a corresponding one of sub-sources 372, 374 and 376 (e.g.,“tile source”) with each sub-source being coupled to a respective powersource.

The NAND memory device 200 is alternatively described with reference toa schematic illustration of FIG. 4.

The memory array 200 includes wordlines 202 ₁ to 202 _(N), and bitlines228 ₁ to 228 _(M).

The memory array 200 also includes NAND strings 206 ₁ to 206 _(M). EachNAND string includes charge-storage transistors 208 ₁ to 208 _(N). Thecharge-storage transistors may use floating gate material (e.g.,polysilicon) to store charge, or may use charge-trapping material (suchas, for example, silicon nitride, metallic nanodots, etc.) to storecharge.

The charge-storage transistors 208 are located at intersections ofwordlines 202 and strings 206. The charge-storage transistors 208represent non-volatile memory cells for storage of data. Thecharge-storage transistors 208 of each NAND string 206 are connected inseries source-to-drain between a source-select device (e.g., source-sideselect gate, SGS) 210 and a drain-select device (e.g., drain-side selectgate, SGD) 212. Each source-select device 210 is located at anintersection of a string 206 and a source-select line 214, while eachdrain-select device 212 is located at an intersection of a string 206and a drain-select line 215. The select devices 210 and 212 may be anysuitable access devices, and are generically illustrated with boxes inFIG. 1.

A source of each source-select device 210 is connected to a commonsource line 216. The drain of each source-select device 210 is connectedto the source of the first charge-storage transistor 208 of thecorresponding NAND string 206. For example, the drain of source-selectdevice 210 ₁ is connected to the source of charge-storage transistor 208₁ of the corresponding NAND string 206 ₁. The source-select devices 210are connected to source-select line 214.

The drain of each drain-select device 212 is connected to a bitline(i.e., digit line) 228 at a drain contact. For example, the drain ofdrain-select device 212 ₁ is connected to the bitline 228 ₁. The sourceof each drain-select device 212 is connected to the drain of the lastcharge-storage transistor 208 of the corresponding NAND string 206. Forexample, the source of drain-select device 212 ₁ is connected to thedrain of charge-storage transistor 208 _(N) of the corresponding NANDstring 206 ₁.

The charge-storage transistors 208 include a source 230, a drain 232, acharge-storage region 234, and a control gate 236. The charge-storagetransistors 208 have their control gates 236 coupled to a wordline 202.A column of the charge-storage transistors 208 are those transistorswithin a NAND string 206 coupled to a given bitline 228. A row of thecharge-storage transistors 208 are those transistors commonly coupled toa given wordline 202.

Three-dimensional integrated structures (e.g., three-dimensional NAND)may have vertically-stacked wordline levels. It can be difficult touniformly deposit conductive material within the wordline levels. Itwould be desirable to develop methods for providing conductive materialwithin the wordline levels. It would also be desirable to develop newarchitectures fabricated utilizing such new methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a block diagram of a prior art memory device having amemory array with memory cells.

FIG. 2 shows a schematic diagram of the prior art memory array of FIG. 1in the form of a 3D NAND memory device.

FIG. 3 shows a cross sectional view of the prior art 3D NAND memorydevice of FIG. 2 in an X-X′ direction.

FIG. 4 is a schematic of a prior art NAND memory array.

FIGS. 5 and 6 are diagrammatic cross-sectional views of an exampleassembly at process stages relative to an example method for fabricatingexample stacked memory cells.

FIG. 5A is a top view of the assembly of FIG. 5. The cross-section ofFIG. 5 is along the line 5-5 of FIG. 5A; and the view of FIG. 5A isalong the line 5A-5A of FIG. 5.

FIG. 7 is a diagrammatic cross-sectional view of a prior art assembly ata process stage following the process stage of FIG. 6.

FIGS. 8-10 are diagrammatic cross-sectional views of an example assemblyat process stages following the process stage of FIG. 6 relative to anexample method for fabricating example stacked memory cells.

FIG. 11 is a diagrammatic cross-sectional view of an example assembly ata process stage following the process stage of FIG. 6 relative to anexample method for fabricating example stacked memory cells.

FIGS. 12-15 are diagrammatic cross-sectional views of regions labelled“P” and “D” of FIG. 11 illustrating example embodiments.

FIGS. 14A and 14B are diagrammatic cross-sectional views of a regionlabeled E of FIG. 14 illustrating example embodiments.

FIGS. 15A and 15B are diagrammatic cross-sectional views of a regionlabeled F of FIG. 15 illustrating example embodiments.

FIGS. 16-18 are diagrammatic cross-sectional views of an exampleassembly at process stages following the process stage of FIG. 11relative to an example method for fabricating example stacked memorycells.

FIG. 18A is a top view of the assembly of FIG. 18. The cross-section ofFIG. 18 is along the line 18-18 of FIG. 18A; and the view of FIG. 18A isalong the line 18A-18A of FIG. 18.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Some embodiments include new methods for depositing conductive wordlinematerial within assemblies comprising vertically-stacked memory cells(e.g., three-dimensional NAND memory arrays). Some embodiments includenew structures formed utilizing the new methods described herein.Example embodiments are described with reference to FIGS. 5, 6 and 8-18.FIG. 7 is provided to illustrate a prior art process stage forcomparison relative to methods of the present invention.

Referring to FIGS. 5 and 5A, a construction 10 (which may also bereferred to as an integrated assembly, or as an integrated structure)includes a stack 14 of alternating first and second levels 16 and 18.

The first levels 16 comprise insulative material 17, and the secondlevels 18 comprise voids 19. The levels 16 and 18 may be of any suitablethicknesses. The levels 16 may be of different thicknesses than thelevels 18, or may be the same thicknesses as the levels 18.

The insulative material 17 may comprise any suitable composition orcombination of compositions; and in some embodiments may comprise,consist essentially of, or consist of silicon dioxide.

Ultimately, conductive wordlines (discussed below) are formed within thesecond levels 18, and such wordlines comprise control gates for memorycells. In some embodiments, the levels 18 may be referred to as memorycell levels of a NAND configuration. The NAND configuration can includea string of memory cells (a NAND string), with the number of memorycells in the string being determined by the number of memory cell levels18. The NAND string may comprise any suitable number of memory celllevels. For instance, the NAND string may have 8 memory cell levels, 16and memory cell levels, 32 memory cell levels, 64 memory cell levels,512 memory cell levels, 1024 memory cell levels, etc.

Structures 20 extend through the stack 14. The structures 20 may bereferred to as channel material structures in that they comprise channelmaterial 22. The channel material 22 comprises semiconductor material;and may comprise any suitable composition or combination ofcompositions. For instance, the channel material 22 may comprise one ormore of silicon, germanium, III/V semiconductor materials, semiconductoroxides, etc.

Tunneling material (sometimes referred to as gate dielectric) 24,charge-storage material 26 and charge-blocking material 28 are betweenthe channel material 22 and the vertically-stacked levels 16/18. Thetunneling material, charge-storage material and charge-blocking materialmay comprise any suitable compositions or combinations of compositions.

In some embodiments, the tunneling material 24 may comprise, forexample, one or more of silicon dioxide, aluminum oxide, hafnium oxide,zirconium oxide, etc.

In some embodiments, the charge-storage material 26 may comprisecharge-trapping materials, such as silicon nitride, silicon oxynitride,conductive nanodots, etc. In alternative embodiments (not shown),charge-storage material 26 may be configured as floating gate material(such as, for example, polycrystalline silicon).

In some embodiments, the charge-blocking material 28 may comprise one ormore of silicon dioxide, aluminum oxide, hafnium oxide, zirconium oxide,etc.

In the illustrated embodiment, the channel material 22 is configured asan annular ring within each of the structures 20. Insulative material 30fills such annular rings. The insulative material 30 may comprise anysuitable composition or combination of compositions, such as, forexample, silicon dioxide. The illustrated structures 20 may beconsidered to comprise hollow channel configurations, in that theinsulative material 30 is provided within “hollows” in theannular-ring-shaped channel configurations. In other embodiments (notshown), the channel material may be configured as a solid pillarconfiguration.

The channel material structures 20 may be considered to comprise all ofthe materials 22, 24, 26, 28 and 30, in combination. The top view ofFIG. 5A shows that the channel material structures 20 may be arranged ina hexagonally-packed pattern.

Slits 32 extend through the stack 14. The slits 32 provide access to allof the voids 19 so that such voids may be filled with conductivematerial during subsequent processing (described below). Although thecross-sectional view of FIG. 5 shows internal voids 19 (i.e., thecentrally-located voids) which appear to be blocked from slits 32 byintervening channel material structures 20, it is to be understood thatthe voids 19 weave around the channel material structures 20.Accordingly, all of the voids 19 along the cross-sectional view of FIG.5 may be fully accessed through the illustrated slits 32.

The voids 19 may be considered to comprise peripheral boundaries (i.e.,edges) 21. The peripheral boundaries may be considered to have proximalregions 23 near the slits 32, and to have distal regions 25 more distantfrom the slits than the proximal regions 23. In some aspects, the distalregions 25 may be considered to be spaced from the slits 32 by theproximal regions 23.

The stack 14 is over a supporting base 12. The base 12 may comprisesemiconductor material; and may, for example, comprise, consistessentially of, or consist of monocrystalline silicon. The base 12 maybe referred to as a semiconductor substrate. The term “semiconductorsubstrate” means any construction comprising semiconductive material,including, but not limited to, bulk semiconductive materials such as asemiconductive wafer (either alone or in assemblies comprising othermaterials), and semiconductive material layers (either alone or inassemblies comprising other materials). The term “substrate” refers toany supporting structure, including, but not limited to, thesemiconductor substrates described above. In some applications, the base12 may correspond to a semiconductor substrate containing one or morematerials associated with integrated circuit fabrication. Such materialsmay include, for example, one or more of refractory metal materials,barrier materials, diffusion materials, insulator materials, etc.

A gap is shown between the base 12 and the stack 14 to diagrammaticallyindicate that there may be one or more additional materials, components,etc., provided between the base 12 and the stack 14. Such additionalcomponents may include, for example, conductive source lines, selectgates, etc.

The stack 14 of FIG. 5 may be formed with any suitable processing. Anexample process may comprise initially forming the stack to includesacrificial material within the levels 18 (such sacrificial material maybe silicon nitride in some example embodiments), and then removing thesacrificial material after forming the channel material structures 20and the slits 32 to leave the construction of FIG. 5.

Referring to FIG. 6, insulative material 34 is deposited along theperipheral boundaries 21 of the voids 19. The material 34 may compriseadditional charge-blocking material; and may comprise any suitablecomposition or combination of compositions. In some embodiments, thematerial 34 may comprise high-k material (for instance, one or more ofaluminum oxide, hafnium oxide, zirconium oxide, tantalum oxide, etc.);where the term “high-k” means a dielectric constant greater than that ofsilicon dioxide. Although the insulative material 34 is shown to be asingle homogenous material, in other embodiments the insulative materialmay comprise two or more discrete compositions. For instance, in someembodiments the insulative material 34 may comprise a laminate ofsilicon dioxide and one or more high-k materials. In some embodiments,the material 34 may be considered to form liners within the voids 19. Insome embodiments, the charge-blocking material 28 may be omitted so thatthe material 34 is the only charge-blocking material provided within theassembly of construction 10.

The insulative material 34 may be formed by flowing appropriateprecursors through the slits 32 in a deposition process (for instance,an atomic layer deposition process, a chemical vapor deposition process,etc.). The insulative material 34 is shown to extend across both theproximal regions 23 and the distal regions 25 of the peripheralboundaries 21 of the voids 19.

In subsequent processing, conductive material is provided to fill thevoids 19 and form conductive wordlines. However, it is found to bedifficult to uniformly fill the voids utilizing conventional processes.FIG. 7 shows construction 10 at a processing stage of a prior artprocess, and illustrates a problem encountered in attempting to fill thevoids 19 with a conductive material 36 utilizing conventionalprocessing. Specifically, the conductive material 36 may pinch-off alongthe proximal regions 23 before filling the voids 19 along the distalregions 25. Accordingly, the distal regions 25 of the voids 19 are notuniformly filled. Such may problematically lead to reduced conductance(i.e., increased resistance) along the conductive wordlines, to excesspower being utilized by memory fabricated within the assembly ofconstruction 10, to excess heat generated during utilization of memoryfabricated within the assembly of construction 10; and may even lead todevice failure.

In the illustrated embodiment of FIG. 7, the conductive material 36 isformed over a conductive liner material 38. In some applications, theconductive liner material 38 may comprise tungsten nitride and theconductive material 36 may comprise tungsten. The liner material 38 maybe a material which can be adhered to the insulative material 34, andwhich provides a surface suitable for adhering the conductive material36.

Some embodiments include methodology which may be utilized to moreuniformly deposit conductive material within the voids 19.

Referring to FIG. 8, such shows construction 10 at a processing stagefollowing that of FIG. 6 in accordance with an example embodiment. Aconductive material 40 is deposited within the voids 19 under conditionssuch that the material is selectively formed within the distal regions25 relative to the proximal regions 23. The material 40 may be a seedmaterial which is subsequently utilized to promote growth of theconductive material 36 (described below with reference to FIG. 9). Thematerial 40 lines the distal regions 25 of the voids 19, and in someembodiments may be referred to as a seed material liner. The material 40may comprise any suitable composition or combination of compositions. Insome embodiments, the seed material may comprise, consist essentiallyof, or consist of one or more metals selected from the group consistingof tungsten, titanium and cobalt. In some embodiments, the seed materialmay include one or more of tungsten, titanium and cobalt; and mayfurther include one or more of nitrogen, aluminum, silicon, oxygen,carbon and germanium. In some embodiments, the seed material 40 maycomprise, consist essentially of, or consist of metal nitride (forinstance, one or more of tungsten nitride, titanium nitride, etc.).

The seed material 40 is deposited by providing appropriate precursorsinto the voids 19 through the slits 32. In some embodiments, the seedmaterial 40 is selectively deposited over the distal regions 25 relativeto the proximal regions 23. Such selective deposition may beaccomplished utilizing atomic layer deposition (ALD) with tuned pulseswhich inhibit a rate of deposition of the seed material 40 along theproximal regions 23 relative to a rate of deposition of the seedmaterial along the distal regions 25. The desired inhibition may beachieved by, for example, including components within the ALD whichinterfere with the deposition process along the proximal regions 23, butwhich are sterically or otherwise precluded from penetrating into thedistal regions 25 to interfere with the deposition process along suchdistal regions. Alternatively, the seed material 40 may be formed intothe configuration of FIG. 8 by initially depositing the seed material tocover the distal regions 25 and at least portions of the proximalregions 23, and then utilizing one or more etchants to selectivelyremove the seed material from the proximal regions 23 while leaving theseed material over the distal regions 25. Such etchant(s) may beprovided under substantially anisotropic etching conditions to keep theetchant(s) along the proximal regions 23 and out of the distal regions25; and/or the etchant(s) may be sterically limited from penetratinginto the distal regions 25.

Referring to FIG. 9, the conductive material 36 is deposited onto theseed material 40. Such deposition may include any suitable methodology,including, for example, one or more of atomic layer deposition, chemicalvapor deposition, physical vapor deposition, etc. The conductivematerial 36 selectively grows over the seed material 40 relative toexposed surfaces of the insulative material 34, and accordinglyselectively grows along the distal regions 25 relative to the proximalregions 23. Thus, the conductive material 36 may be uniformly grownalong the distal regions 25 without the detrimental pinching-off alongthe proximal regions 23 describe relative to the prior art process stageof FIG. 7.

The conductive material 36 may comprise a different composition relativeto the seed material 40. In some embodiments, the conductive material 36may be referred to as a metal-containing material; and suchmetal-containing material may comprise, consist essentially of, orconsist of one or more of tungsten, titanium, ruthenium, cobalt, nickeland molybdenum. In some embodiments, the metal-containing material 36may include a metal carbide and/or a metal silicide. For instance, themetal-containing material 36 may include one or more of tungsten,titanium, ruthenium, cobalt, nickel and molybdenum; and may furtherinclude one or both of carbon and silicon.

Referring to FIG. 10, a remaining portion of conductive material 36 isgrown within the proximal regions 23; with such remaining portion of theconductive material 36 also filling the slits 32. In subsequentprocessing analogous to that described below with reference to FIGS. 17and 18, the material 36 may be removed from within the slits andreplaced by insulative panels. Such forms conductive wordlines along thelevels 18, with such wordlines comprising the conductive materials 36and 40.

The methodology of FIGS. 8-10 illustrates an example embodiment in whichmetal-containing material is deposited within the voids 19 underconditions which cause the metal-containing material to form to agreater thickness along the distal regions 25 relative to the proximalregions 23 for an initial duration of the deposition. Such canalleviate, and preferably prevent, the pinching-off problems describedabove with reference to the prior art process stage of FIG. 7. In theembodiment of FIGS. 8-10, both of the materials 40 and 36 are depositedunder conditions which cause the metal-containing materials to form to agreater thickness along the distal regions 25 relative to the proximalregions 23 for initial durations of the depositions. In the case of thematerial 40, such is formed to a greater thickness along the distalregions 25 relative to the proximal regions 23 for the entire durationof the deposition of such material.

FIGS. 11-16 illustrate additional example embodiments in whichmetal-containing material may be deposited within the voids 19 underconditions which cause the metal-containing material to form to agreater thickness along the distal regions 25 relative to the proximalregions 23 for an initial duration of the deposition.

Referring to FIG. 11, construction 10 is shown at a process stage whichmay follow that of FIG. 6. A seed material 50 is formed along theinsulative material 34 within the voids 19; with the seed material 50lining the voids 19. In the shown embodiment, the seed material 50extends along both the proximal regions 23 and the distal regions 25.The seed material 50 may comprise any suitable composition orcombination of compositions; and may or may not be conductive. In someembodiments, the seed material 50 is a metal-containing seed material;and may comprise, consist essentially of, or consist of one or moremetals selected from the group consisting of tungsten, titanium andcobalt. In some embodiments, the seed material 50 may include one ormore of tungsten, titanium and cobalt; and may further include one ormore of nitrogen, aluminum, silicon, oxygen, carbon and germanium. Insome embodiments, the seed material 50 may comprise, consist essentiallyof, or consist of metal nitride (for instance, one or more of tungstennitride, titanium nitride, etc.).

The seed material 50 may comprise a different composition along thedistal regions 25 relative to the proximal regions 23. In someembodiments, such difference in composition may enhance growth of theconductive material 36 (FIG. 16) along the distal regions relative tothe proximal regions and/or may inhibit growth of the conductivematerial along the proximal regions relative to the distal regions.Regardless, the difference in composition of seed material 50 along thedistal regions 25 relative to the proximal regions 23 may enable themetal-containing material 36 to form to a greater thickness along thedistal regions relative to the proximal regions for an initial durationas the material 36 is deposited within the voids 19.

A portion of construction 10 comprising a proximal region 23 is labeledas a region “P”, and a portion of the construction comprising a distalregion 25 is labeled as a region “D”. The regions P and D are shown inFIG. 12. The seed material 50 along the proximal region 23 is part of afirst portion 52 of the seed material which has a first surface 51having a first surface composition, and the seed material 50 along thedistal region 25 is part of a second portion 54 of the seed materialwhich has a second surface 53 having a second surface composition. Thefirst and second surface compositions are different from one another,and the metal-containing material 36 (FIG. 16) grows faster along thecomposition of surface 53 than along the composition of surface 51.

FIG. 13 shows an example embodiment in which dopant (illustrated bystippling) is provided within the material 50 along the proximal regions23, and is not provided (or is provided to a lower concentration) withinthe material 50 along the distal regions 25. The dopant may slow growthof metal-containing composition 36 (FIG. 16) along the first surfaces 51of the material 50 relative to the second surfaces 53, and in someembodiments may completely inhibit the growth of the metal-containingcomposition 36 along the first surfaces 51 of the material 50. Thedopant may inhibit the growth of the metal-containing composition 36 byany suitable mechanism. For instance, in some embodiments the dopant mayinhibit the growth of the metal-containing material 36 by slowingnucleation of the metal-containing material during a deposition process.Accordingly, the nucleation of the metal-containing material 36 will beslower along the proximal regions 23 than along the distal regions 25,which will result in faster growth of the metal-containing materialalong the distal regions 25. Regardless of the mechanism by which thegrowth along the proximal regions 23 is inhibited relative to the growthalong the distal regions 25, the relatively faster growth of themetal-containing material 36 along the distal regions 25 may enable allof the voids 19 to be uniformly filled with the material (as illustratedin FIG. 16).

The dopant may be provided within the slits 32 (FIG. 11) underconditions in which the dopant migrates primarily into the portions ofthe seed material 50 along the proximal regions 23 (i.e., the portion 52of FIG. 13), and does not migrate into the portions of the seed material50 along the distal regions 25 (i.e., the portion 54 of FIG. 13). Suchmay be achieved by providing the dopant under relatively low-powerconditions, low bias conditions, etc.; and/or by utilizing dopant whichis sterically hindered from migrating deeply into the voids 19.

The processing stage of FIG. 13 may be achieved utilizing any suitablecomposition of seed material 50, and any suitable dopant.

In some embodiments, the seed material 50 may comprise one or both oftungsten and titanium in combination with nitrogen, and the dopant maycomprise boron.

In some embodiments, the seed material 50 may comprise one or both oftungsten and titanium, and the dopant may comprise one or both of boronand nitrogen. For instance, in some embodiments the composition 50 maycomprise tungsten in combination with nitrogen, and the portion 52 ofmaterial 50 along the proximal region 23 may comprise a higher nitrogenconcentration than the portion 54 along the distal region 25. Forinstance, the portion 54 of material 50 may comprise stoichiometrictungsten nitride (e.g., WN or W₂N depending on the depositionconditions), while the portion 52 of material 50 comprises aconcentration of nitrogen in excess of the stoichiometric amount. Theportion 52 may additionally comprise boron.

As another example, composition 50 may comprise titanium in combinationwith nitrogen, and the portion 52 of material 50 along the proximalregions 23 may comprise a higher concentration of nitrogen than theportion 54 along the distal region 25. The portion 52 may additionallycomprise boron.

In some embodiments, the first and second portions 52 and 54 of the seedmaterial may both comprise metal, but the first and second surfaces 51and 53 may comprise different metal-containing compositions relative toone another. For instance, the first surface 51 may primarily comprise(i.e., may comprise more than 50 atomic percent) of a firstmetal-containing composition, while the second surface 53 primarilycomprises a second metal-containing composition different from the firstmetal-containing composition. Example embodiments are described withreference to FIGS. 14 and 15.

Referring to FIG. 14, the seed material 50 may comprise a basecomposition (i.e. first composition) 60 which extends across an entiretyof the seed material (i.e., extends across both of the portions 52 and54 of FIG. 14). The base composition may include one or more oftungsten, titanium and cobalt; and in some embodiments may furtherinclude one or more of nitrogen, aluminum, silicon, oxygen, carbon andgermanium. The base composition is the only composition within theportion 54 of the seed material 50 along the distal region 25. Incontrast, the seed material 50 includes a second composition 62 over thebase composition 60 within the portion 52 of the seed material along theproximal region 23. The second composition 62 is different from thefirst composition 60. In some embodiments, the second composition 62 mayinclude one or more of tungsten, titanium and cobalt; and in someembodiments may further include one or more of nitrogen, aluminum,silicon, oxygen, carbon and germanium.

The second composition 62 may inhibit growth of the conductive material36 (FIG. 16) relative to the first composition 60. Accordingly, theconductive material 36 may be deposited to uniformly fill all of thevoids 19 (as illustrated in FIG. 16). In some embodiments, ametal-containing material 36 comprising tungsten will grow more rapidlyover titanium nitride than over tungsten nitride. Accordingly, thesurface 51 of the seed material 50 along the proximal regions 23 mayprimarily comprise tungsten nitride, while the surface 53 of the seedmaterial 50 along the distal regions 25 primarily comprises titaniumnitride. Accordingly, the composition of the surface 51 of the seedmaterial 50 along proximal regions 23 may retard growth of themetal-containing material 36 relative to the composition of the surface53 along the distal regions 25.

The second composition 62 may be formed as a laminate over the firstcomposition 60 (as shown in FIG. 14A relative to a region labeled “E” inFIG. 14), or may be formed as a gradient extending upwardly from thefirst composition 60 (as shown in FIG. 14B relative to the region E).The gradient of metal within the second composition 62 isdiagrammatically represented in FIG. 14B by showing an increase inconcentration of the metal (with the metal concentration being shown as“[X]”) from the bottom of the composition 62 to the top of thecomposition 62.

In some embodiments, the first and second portions 60 and 62 may bothcomprise two or more metals, and a relative proportion of the metals mayvary in the second portion 62 relative to the first portion 60. Forinstance, in some embodiments it is found that a metal-containingmaterial 36 comprising tungsten will grow more rapidly over titaniumnitride than over tungsten nitride. The first and second portions 60 and62 may both comprise a combination of titanium nitride and tungstennitride, and the relative amount of tungsten nitride may be higher inthe region 62 than in the base region 60. For instance, in someembodiments the region 62 may primarily comprise tungsten nitride, whilethe region 60 primarily comprises titanium nitride. A dashed line isutilized in FIG. 14B to indicate that the metal-containing material(e.g., tungsten nitride) within portion 62 of the base 50 is present inboth of the portions 60 and 62 of material 50, with [X] indicating theincreasing amount of such metal-containing material along a gradienttoward a surface of the portion 62.

In some embodiments, the first and second portions 60 and 62 maycomprise two or more metals selected from the group consisting oftungsten, titanium and cobalt, with one of said two or more metals beinga primary component of the base portion 60, and the other being aprimary component of the second portion 62. The metals may be part ofmetal-containing compositions; and in some embodiments may be in theform of one or more of metal carbide, metal silicide, metal nitride,etc.

FIG. 15 shows an embodiment analogous to that of FIG. 14, except thatthe additional material (second material) 62 is provided over theportion 54 of material 50 along the distal regions 25, rather than beingprovided over the portion 52 of the material 50 along the proximalregions 23. In the embodiment of FIG. 14, the second material 62 wasutilized to retard growth of metal-containing material 36 (FIG. 16)along the proximal regions 23. In contrast, the second material 62utilized in the embodiment of FIG. 15 may be provided to enhance growthof the metal-containing material 36 along the distal regions 25. Forinstance, in some embodiments the base material 60 of FIG. 15 maycomprise tungsten nitride, the second material 62 may comprise titaniumnitride, and the metal-containing material 36 (FIG. 16) may comprisetungsten.

The constructions of FIGS. 14 and 15 may be formed with any suitableprocessing. For instance, the base region 60 of seed material 50 may beinitially deposited under conditions which form the base region 60 to beof substantially uniform thickness along the proximal regions 23 anddistal regions 25 (with the term “substantially uniform thickness”meaning uniform thickness to within reasonable tolerances of fabricationand measurement). Subsequently, the additional region 62 of basematerial 50 may be deposited under conditions which either form theadditional region 62 primarily along the proximal regions 23 as opposedto the distal regions 25 (for the embodiment of FIG. 14), or which formthe additional region 62 primarily along the distal regions 25 asopposed to the proximal regions 23 (for the embodiment of FIG. 15). Thedeposition of the composition of the additional region 62 may becontrolled by, for example, bias conditions, power conditions, stearicproperties of one or more precursors, etc., in order to provide suchcomposition to be primarily over one of the proximal/distal regions23/25 relative to the other of the proximal/distal regions 23/25.

Referring to FIG. 16, the construction 10 is shown at a process stagefollowing that of FIG. 11. The conductive material 36 is provided withinthe slits 32, and is deposited within the voids 19. The seed material 50of FIG. 16 may comprise distal regions 25 and proximal regions 23 whichare modified relative to one another in accordance with the embodimentsdescribed with reference to FIGS. 11-15. The material 36 uniformlydeposits within the voids 19 due to the material 36 forming to a greaterthickness along the distal regions 25 relative to the proximal regions23 during an initial duration of the deposition.

Referring to FIG. 17, conductive material 36 is removed from slits 32with one or more suitable etches. The remaining conductive material 36forms conductive wordlines 64 along the second levels 18.

Referring to FIGS. 18 and 18A, the slits 32 are filled with insulativematerial 68. The insulative material 68 within the slits is configuredas panels 70 which extend longitudinally along an axis 5 (providedadjacent the top view of FIG. 18A).

The wordlines 64 comprise gate regions 72 adjacent the channel materialstructures 20; and the gate regions together with materials in thechannel material structures form a plurality of vertically-stackedmemory cells 74. Such memory cells may be NAND memory cells of athree-dimensional NAND memory array. In some embodiments, the insulativepanels 70 may be utilized to subdivide the memory array amongst blocks,or at least partial blocks, (with a “block” corresponding to acollection of memory cells which are erased simultaneously in ablock-erase operation).

The conductive material 36 within the second levels 18 (i.e., theconductive wordlines 64) may be considered to comprise outer edges 37.Such outer edges have proximal regions 43 near the panels 70, and alongthe proximal regions 23 discussed above with reference to FIG. 5. Theouter edges 37 of the conductive wordlines 64 also comprise distalregions 45 along the distal regions 25 discussed above with reference toFIG. 5. The distal regions 45 are spaced from the insulative panelstructures 70 by the proximal regions 43. The seed material 50 may beconsidered to be an interface material between the outer edges 37 of thewordlines 64 and the insulative material 34. The interface material 50is along the outer edges 37 of the wordline 64 (i.e., is along the outeredges of the conductive material 36).

The interface material 50 may comprise a different composition along theproximal regions 43 of the outer edges 37 than along the distal regions45 of the outer edges 37; and specifically, may comprise thecompositions described above with reference to FIGS. 8-15.

In some embodiments, the interface material 50 may include boron (orother suitable dopant) along the proximal regions 43 of the outer edges37, and not along the distal regions 45 of the outer edges.

In some embodiments, the interface material 50 may include two or moremetals, with one of the metals being a primary component along theproximal regions 43, and another of the metals being a primary componentalong the distal regions 45.

In some embodiments, the interface material 50 may comprise tungstennitride and titanium nitride, with the tungsten nitride being a primarycomponent adjacent the surfaces 37 of the conductive material 36 withinproximal regions 43, and with the titanium nitride being a primarycomponent adjacent the surfaces 37 of the conductive material 36 withinthe distal regions 45.

In some embodiments, the interface material 50 may be a metal-containinginterface material comprising two or more metals. A first metal of saidtwo or more metals may be the primary metal of a first surfacecomposition along the proximal regions 43 of the surfaces 37 ofwordlines 64 (i.e., the surfaces 37 of the conductive material 36 withinthe second levels 18), and a second metal of said two or more metals maybe the primary metal of a second surface composition along the distalregions 45 of the surfaces 37. In some embodiments, the first and secondsurface compositions may comprise metal nitrides. For instance, thefirst surface composition (i.e., the composition of interface material50 along proximal regions 43) may comprise tungsten nitride, and thesecond surface composition (i.e., the composition of interface material50 along the distal regions 45) may comprise titanium nitride.

In some embodiments, the first and second surface compositions maycorrespond to surfaces along the first and second portions 60 and 62 ofmaterial 50 described above with reference to FIGS. 14 and 15. The“first surface composition” may be either of the first and secondportions 60 and 62, and the “second surface composition” will be theother of the first and second portions 60 and 62. In some embodiments,the portions 60 and 62 may be comprised by a laminate structure (FIGS.14A and 15A), or a gradient structure (FIGS. 14B and 15B).

The assemblies discussed above may be incorporated into electronicsystems. Such electronic systems may be used in, for example, memorymodules, device drivers, power modules, communication modems, processormodules, and application-specific modules, and may include multilayer,multichip modules. The electronic systems may be any of a broad range ofsystems, such as, for example, cameras, wireless devices, displays, chipsets, set top boxes, games, lighting, vehicles, clocks, televisions,cell phones, personal computers, automobiles, industrial controlsystems, aircraft, etc.

Unless specified otherwise, the various materials, substances,compositions, etc. described herein may be formed with any suitablemethodologies, either now known or yet to be developed, including, forexample, atomic layer deposition (ALD), chemical vapor deposition (CVD),physical vapor deposition (PVD), etc.

The terms “dielectric” and “insulative” may be utilized to describematerials having insulative electrical properties. The terms areconsidered synonymous in this disclosure. The utilization of the term“dielectric” in some instances, and the term “insulative” (or“electrically insulative”) in other instances, may be to providelanguage variation within this disclosure to simplify antecedent basiswithin the claims that follow, and is not utilized to indicate anysignificant chemical or electrical differences.

The particular orientation of the various embodiments in the drawings isfor illustrative purposes only, and the embodiments may be rotatedrelative to the shown orientations in some applications. Thedescriptions provided herein, and the claims that follow, pertain to anystructures that have the described relationships between variousfeatures, regardless of whether the structures are in the particularorientation of the drawings, or are rotated relative to suchorientation.

The cross-sectional views of the accompanying illustrations only showfeatures within the planes of the cross-sections, and do not showmaterials behind the planes of the cross-sections, unless indicatedotherwise, in order to simplify the drawings.

When a structure is referred to above as being “on” or “against” anotherstructure, it can be directly on the other structure or interveningstructures may also be present. In contrast, when a structure isreferred to as being “directly on” or “directly against” anotherstructure, there are no intervening structures present.

Structures (e.g., layers, materials, etc.) may be referred to as“extending vertically” to indicate that the structures generally extendupwardly from an underlying base (e.g., substrate). Thevertically-extending structures may extend substantially orthogonallyrelative to an upper surface of the base, or not.

Some embodiments include a method of forming an integrated structure. Anassembly is formed to include a stack of alternating first and secondlevels. The first levels are insulative levels which comprise insulativematerial. The second levels comprise voids between the insulativelevels. The assembly includes channel material structures extendingthrough the stack, and includes slits extending through the stack. Thevoids have peripheral boundaries, and open into the slits. Theperipheral boundaries have proximal regions near the slits and distalregions spaced from the slits by the proximal regions. Ametal-containing material is deposited within the voids under conditionswhich cause the metal-containing material to form to a greater thicknessalong the distal regions relative to the proximal regions for an initialduration of the of the deposition.

Some embodiments include an assembly having a stack of alternating firstand second levels. The first levels include insulative material, and thesecond levels include conductive material. The assembly includes channelmaterial structures extending through the stack, and includes insulativepanel structures extending through the stack. The conductive materialwithin the second levels has outer edges. The outer edges have proximalregions near the insulative panel structures and distal regions spacedfrom the insulative panel structures by the proximal regions. Interfacematerial is along the outer edges of the conductive material. Theinterface material has a different composition along the proximalregions of the outer edges than along the distal regions of the outeredges.

Some embodiments include an assembly having a stack of alternating firstand second levels. The first levels comprise insulative material, andthe second levels comprise conductive material. The assembly includeschannel material structures extending through the stack, and includesinsulative panel structures extending through the stack. The conductivematerial within the second levels has outer edges. The outer edges haveproximal regions near the insulative panel structures and distal regionsspaced from the insulative panel structures by the proximal regions.Metal-containing interface material is along the outer edges of theconductive material. The metal-containing interface material has a firstsurface composition along the proximal regions of the outer edges andhas a second surface composition along the distal regions of the outeredges. The metal-containing interface material comprises two or moremetals. A first metal of said two or more metals is the primary metal ofthe first surface composition, and a second metal of said two or moremetals is the primary metal of the second surface composition.

In compliance with the statute, the subject matter disclosed herein hasbeen described in language more or less specific as to structural andmethodical features. It is to be understood, however, that the claimsare not limited to the specific features shown and described, since themeans herein disclosed comprise example embodiments. The claims are thusto be afforded full scope as literally worded, and to be appropriatelyinterpreted in accordance with the doctrine of equivalents.

1-33. (canceled)
 34. A method of forming an integrated structure,comprising: forming an assembly to include a stack of alternating firstand second levels; the first levels being insulative levels comprisinginsulative material, and the second levels comprising voids between theinsulative levels; the assembly including channel material structuresextending through the stack, and including slits extending through thestack; the voids having peripheral boundaries, and opening into theslits; the peripheral boundaries having proximal regions near the slitsand distal regions spaced from the slits by the proximal regions; anddepositing a metal-containing material within the voids under conditionswhich cause the metal-containing material to form to a greater thicknessalong the distal regions relative to the proximal regions for an initialduration of the of the deposition; and wherein the deposition conditionsutilize a seed material along the distal regions, and utilize growth ofthe metal-containing material over the seed material.
 35. The method ofclaim 34 wherein the metal-containing material comprises one or more oftungsten, titanium, ruthenium, cobalt, nickel and molybdenum.
 36. Themethod of claim 34 comprising forming the seed material utilizing atomiclayer deposition with tuned pulses which inhibit a rate of deposition ofthe seed material along the proximal regions relative to a rate ofdeposition of the seed material along the distal regions.
 37. The methodof claim 34 wherein the seed material has a different composition alongthe proximal regions than along the distal regions.
 38. The method ofclaim 37 wherein the seed material includes one or more metals selectedfrom the group consisting of tungsten, titanium and cobalt.
 39. Themethod of claim 38 wherein the seed material further includes one ormore of nitrogen, aluminum, silicon, oxygen, carbon and germanium. 40.The method of claim 37 wherein the composition of the seed materialalong the distal regions enhances growth of the metal-containingmaterial relative to the composition of the seed material along theproximal regions.
 41. The method of claim 40 wherein the seed materialcomprises a combination of tungsten nitride and titanium nitride;wherein the metal-containing material comprises tungsten; and whereinsurfaces of the seed material along the distal regions have a higheramount of titanium nitride relative to tungsten nitride than surfaces ofthe seed material along the proximal regions.
 42. The method of claim 41wherein the surfaces of the seed material along the distal regions areprimarily titanium nitride, and the surfaces of the seed material alongthe proximal regions are primarily tungsten nitride.
 43. The method ofclaim 37 wherein the composition of the seed material along the proximalregions retards growth of the metal-containing material relative to thecomposition of the seed material along the distal regions.
 44. Themethod of claim 43 wherein the composition of the seed material alongthe proximal regions comprises a dopant which is lacking from thecomposition of the seed material along the distal regions.
 45. Anassembly, comprising: a stack comprising first and second levels; thefirst levels comprising insulative material, and the second levelscomprising conductive material; insulative panel structures extendingthrough the stack; the conductive material within the second levelshaving outer edges; the outer edges having proximal regions near theinsulative panel structures and distal regions spaced from theinsulative panel structures by the proximal regions; and interfacematerial along the outer edges of the conductive material, the interfacematerial having a first composition along the proximal regions of theouter edges, and having a second composition along the distal regions ofthe outer edges; the first composition being different than the secondcomposition.
 46. The assembly of claim 45 wherein the conductivematerial comprises one or more of tungsten, titanium, ruthenium, cobalt,nickel and molybdenum.
 47. The assembly of claim 45 wherein theconductive material comprises one or both of a metal silicide and ametal carbide.
 48. The assembly of claim 45 wherein the interfacematerial includes two or more metals selected from the group consistingof tungsten, titanium and cobalt; with one of said two or more metalsbeing a primary component of the first composition, and with another ofsaid two or more metals being a primary component of the secondcomposition.
 49. The assembly of claim 48 wherein the interface materialfurther includes one or more of nitrogen, aluminum, silicon, oxygen,carbon and germanium.
 50. An assembly, comprising: a stack over asemiconductor substrate; the stack comprising first and second levels;the first levels comprising insulative material, and the second levelscomprising conductive material; the assembly including channel materialstructures extending through the stack, and including insulative panelstructures extending through the stack; the conductive material withinthe second levels having outer edges; the outer edges having proximalregions near the insulative panel structures and distal regions spacedfrom the insulative panel structures by the proximal regions; thesemiconductor substrate comprising silicon; and metal-containinginterface material along the outer edges of the conductive material; themetal-containing interface material having a first surface compositionalong the proximal regions of the outer edges and having a secondsurface composition along the distal regions of the outer edges; themetal-containing interface material comprising two or more metals; afirst metal of said two or more metals being the primary metal of thefirst surface composition, and a second metal of said two or more metalsbeing the primary metal of the second surface composition.
 51. Theassembly of claim 50 wherein the first and second surface compositionscomprise metal nitrides.
 52. The assembly of claim 50 wherein the firstmetal is tungsten and the second metal is titanium.
 53. The assembly ofclaim 52 wherein the interface material comprises a base materialsupporting the first and second surface compositions, and wherein thebase material is a same composition as one of the first and secondsurface compositions.
 54. The assembly of claim 53 wherein the basematerial is a same composition as the first surface composition.
 55. Theassembly of claim 53 wherein the base material is a same composition asthe second surface composition.
 56. The assembly of claim 53 whereinsaid one of the first and second surface compositions is a laminate overthe base material.
 57. The assembly of claim 53 wherein said one of thefirst and second surface compositions is an outer portion of a gradientextending from the base material.